Pasadena Fire Department paramedics treat a young victim at the scene of the tree collapse in the Arroyo outside the Kidspace Children's Museum on July 28, 2015. Photo: Jamie Nichols, Pasadena Fire Department

A mother filed a lawsuit Thursday against the City of Pasadena and the Kidspace Children’s Museum Thursday on behalf of her twins hurt when a tree near the Kidspace Children’s Museum in the Arroyo Seco collapsed onto them last summer as the children were waiting to be picked up by their parents after attending a summer camp session

The complaint names the city and Kidspace and alleges dangerous condition on public property, negligence and premises liability, a report by City News Service said.

Yvonne Yeung, the mother of six-year-old twins Brandon and Bryan Li, filed the suit at the Los Angeles Superior Court on behalf of her sons and the other injured children, said the report.

She was seeking unspecified damages.

The complaint alleged that Brandon suffered fractures to an arm and a leg, and Bryan had a head injury when the tree fell at about 4:30 p.m. on July 28, 2015. It also said both children suffered psychological injuries after the incident.

Yeung said City and museum officials knew of the dangerous condition of the tree but did not take steps to prevent the tree fall. She alleged no barriers were in place to help protect people in case of such a fall.

Six other children were treated on the scene and released that day. The children were waiting for their parents to pick them up after the summer camp session when the accident happened.